Local IP Access (LIPA) is a technology which allows traffic exchanged in a local network not to go through a mobile carrier network.
FIG. 1 is a view illustrating a configuration of a typical local network according to the related art.
Referring to FIG. 1, a structure of a local network which supports LIPA includes a Home Node or Home eNode B (H(e)NB) and a Local Gateway (L-GW) connected to the H(e)NB. A User Equipment (UE) generates a LIPA Packet Data Network (PDN) connection through the L-GW, and may communicate with another Internet Protocol (IP) device within the local network.
Long Term Evolution (LTE) does not support communication of a Circuit Switch (CS) scheme, and supports only communication of a Packet Switch (PS) scheme for transmitting an IP packet. Accordingly, when a UE of an LTE system desires voice communication, a scheme may be used in which the UE of the LTE system is handed over to an existing system. The existing system may be a legacy system such as a Universal Terrestrial Radio Access Network (UTRAN), a GSM EDGE Radio Access Network (GERAN), or the like, which supports the CS scheme, where a voice service is provided to the UE of the LTE system in the CS scheme. This scheme is referred to as “CS Fallback (CSFB).”
When the UE of the LTE system using a LIPA PDN connection uses CSFB in order to transmit and/or receive a voice, the UE of the LTE system cannot use the LTE system any longer, and thus the use of the LIPA PDN connection needs to be stopped. Currently, in a 3rd Generation Partnership Project (3GPP) LTE standard, when the H(e)NB which is a base station of the LTE system is switched to another base station due to the movement of the UE using the LIPA PDN connection or due to a function of using another Radio Access Network (RAN), such as CSFB, the LIPA PDN connection is unconditionally deactivated.
When the UE having the LIPA PDN connection deactivates the LIPA PDN connection due to the CSFB, a session of traffic transmitted and/or received through the LIPA PDN connection does not exist any longer. Specifically, due to the CSFB, the UE cannot communicate with a target IP device by using an identical IP address any longer. When the LIPA PDN connection is deactivated once, after voice communication using the CSFB is terminated, the UE must generate a LIPA PDN connection before receiving a LIPA service again. A new IP address is assigned to the UE. If the LIPA PDN connection is deactivated during the generation of the CSFB as described above, deactivation becomes a main cause of degrading IP-based service quality of the UE simultaneously using the CSFB and a LIPA function.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.